Process of making lithographic plates.



s. A. NEIDICH.

PROCESS QF MAKING LITHOGRAPHIC PLATES. APPLlcATloN FILED Aue.x1.1914.

1,245,1 19. Patented Oct. 30, 1917.

kim/5555's.' Irl/wrom SAMUEL A. NEIDIVCH, 0F EIDGEWATEB PARK, NEW JERSEY, ASSIGNUB. T0 THE AMEEI- y CAN MULTIGRAPH COMANY, 0F CLEVELAND, OHI, A CQRPORATEON 0F OHG.

PROCESS 02E' MAKING LITHOGRAFHC PLATES.

Specicaton of'Letters Patent.

atented iE-ct. 3i), .1191?.

.Application led .august il, 1914. Serial No. 856,201.

2"@ all whom t may concern:

Be it known that I, SAMUEL A. NEIDIGH, a citizen of the United States, residing at Edgewater Park, in the county of Burlington and State of New Jersey, have invented a certain new and useful Improvementy in Processes of Making Lithographie Plates, of which the following is a full, clear, and exact description, reference being had 'to the accompanying drawings.

This invention relates to a process for the preparation of a metal lithographie plate, the object being to reduce the expense, time and skill required in the preparation ofV a plate for printing, as well as to produce a more durable plate and one having other desirable properties hereinafter' mentioned. In the ordinary process of preparing metal lithographic plates, a grained plate has the work or image applied direct to it in some greasy medium andthereafter the balance of the plate is etched and gummedV to make it ink-resisting when moist.

In the old processes it is very important that no grease be present on the grained plate where printing is not desired, and that the plate be kept free romoxidization, and great skill is required as well as considerable time in accomplishing the etching. Inasmuch as the etching operation tends to remove the work, the usual method has been to partially etch the plate and thereafter strengthen the work and then further etch the plate and further strengthen the work,

if necessary.y These successive operations' require great skill and caution, lest thev work be partially removed bythe etching substances. There is great liability of spoiling the plate during this process, for if the etchingremoves the least part of the work, the plate is ruined, or is only pre.- served by tedious subsequent operations. Unless the operation is carried out with the greatest possible care',.the plate lacks durability, as the image is liable to become partially removed during the operation of the printing.

I haveV found that while a plate thoroughly etched is incapable of receiving ink when moist, it is capable of having wax images'rmly aiixed by action of heat. This process relates particularly to reproduction of work of the character of typewriting or matter already existing in the form of type matter, zinc cuts andthe like, and consists sheet of carbon paper containing a maximum percentage of hard wax consistent with its giving ofi? a portion of its surface under the blo-ws of the typewriter to the zinc plate. One of my etched plates, from which any soluble gum has been dissolved,

is now, covered with a sheet of this carbon paper and the two inserted in an ordinary typewriting machine, and the necessary matter typewritten through the carbon onto the zinc plate. I have 'found by experience that a carbon ink of this character when locally deposited on the plate and heated, will become thoroughly xed to the preetched surface and capable of being proceeded with in the ordinary lithographie method without subsequent treatment of any kind.

In order to reduce thetendency of the molten wax to spread the work, I incorporate in the carbon ink a maximum percentage of pigment for the purpose of making -the compound as viscous as possible when molten. While no other step is'necessary for the production of a typewritten lithographic plate, I prefer after depositing the copy on the zinc plate, to coat it with gum and dry the gum, previous to heatin as this overcomes the tendency of typewritten work to spread by the ilow of the wax.

In the reproduction of lithographie matter already existing in the shape of type, zinc cuts or other relief printing surfaces, I lind it is only necessaryto coat the printing surface of the type or other form with a solution of hard wax, preferably carnauba in one of its well-known solvents,as benzol, allowing the solution to evaporate and thus depositing a very thin film of WaX,'on the type surface. The type surface is then brought into contactwith a warm plate and the wax thereby melted, rmlyfattaches to the pretched plate, forming the image for the lithographie work. In this case, the film n Cra graphic negative l prefer take a wax transfer by ordinary photographic means, the same being impressed on the warm plate. lt is a vital characteristic f all of the various operations above described, that there is deposited on the preetchecl plate, a molten hard waa in the ahsence of gum.

The drawings further illustrate my process: in which Figure l is a cross section very much enlarged, of an ordinary grained metal plate; Fig. 2 is a cross section of such plate after the entire face thereof has been etched; Fig. 3 is a cross section after the worli is applied, and Fig. 4 is a. plan of a portion of the plate shown in Fig. 8.

ln Figs. l to 8, A represents the body of the metal plate and a the grained surface thereof; B represents the coating formed by the action of the etching materials on the zinc which is a suhstanee capable when moist, of rejecting ink. T his etching is shown graphically as higher than the grain, though in reality it is incorporated with it. E, in Figs. 3 and l indicates the image which is applied to the etched surface of the plate in the form of a. hard waxy resisting mate-- rial, `which by heating becomes homogeneous and firmly attached to the etched plate.

ln the above description it is to be understood that the word etched is used in the comanonly accepted lithographie meaning of the word, to cover any means cima-king surfaces ink-resisting when moist, and not in the ordinary sense of the word, as meaning cutting away of the metal hy an acid. The word work is used throughout to mean the image which is to receive the inl: and he duplicated in the printing process.

The process described refers more particularly to the production of a plate for the reproduction of work of the character of typewriting, type matter, aine cuts and other work already existing, though my preetched plate is adapted to receive work hy other means, such as antographic work, line drawings, artist sketches, and the reproduction of such work is covered in a copending application of mine, No. 856,202, led iugust ll, wie. The pretched plate itself,

ready to receive work, forms the subject matter of my ljatent 1,208,770, issued Nov. t, wie.

Having thus described my invention, what l claim is:

l. 'llhe process of preparing a metallic lithographie plate consisting of etching the entire face of the plate and applying directly to the etched surface the image in the form of a hard waxy substance capable of being attached to the pretched plate by heat. l

2. rl`he process of preparing lithographie plate consisting of etching the 4entire face of the plate, removing any soluble gumfrom such face, and applying directly to the etched surface the image in the form of a hard waxy substance capable of being attached to the pretched plate by heat.

3. process of preparing a lithographie plate consisting of etching the face of the plate, placing on such etched. face a hard waxy substance defining the image and heat ing the. waxy substance to Valiix such image.

The process of preparing a lithographie plate consisting of etching the entire face of the plate, depositing the work locally in a hard waxy substance, coating the plate with soluble gum and subsequently heating the plate.

5. 'lfhe process of preparing a lithographie plate consisting of etching the entire face of the plate and causing a heated waxy image to adhere to the plate.

S. The process of preparing a lithographie plate consisting in etching the face of the plate and thereafter causing a waxy image to be fixed to the etched surface by heat.

7. The process of preparing a lithographie plate consisting of etching the face of the plate, transferring to the etched surface a design formed of carnauba wax or its equivalent, said design being axed to the plate by heat.

ln testimony whereof, l hereunto ailix my signature in the presence of two witnesses.

SAMUEL A. NElDlCH. lllitnesses JUSTIN W. MACKLIN, Japaner lol. Barns. 

